1. Field of Invention
This invention relates to the control of chainsaw motors and chainsaw chains, to enhance the safety and simplicity of their operation.
2. Description of Prior Art
Chainsaws are universally produced with a trigger that is pressed by the index finger to operate the motor and chain. If this type of chainsaw is dropped by the supporting hand, the saw's weight falls on the trigger finger of the control handle, thereby supplying power to the chain as the chainsaw falls, increasing the likelihood of severe injury or damage.
U.S. Pat. No. 4,121,339 of Oct. 24, 1978, "Safety Brake Mechanism for Chain Saws," by Milovan Nikolich describes a chain-braking system that is operated by the hand that supports the chainsaw, in which the brake is automatically in case of chainsaw kickback, so this chain-stopping mechanism is devised to solve the problem of injury from kickback, but does not address the problem of injury by a chainsaw that is dropped by the supporting hand, only to fall on the trigger finger of the control hand and supply power to the chain as the chainsaw falls.
U.S. Pat. No. 4,683,660 of Aug. 4, 1987, "Chain Saw Having a Braking Arrangement," by Volker Schurr describes a chain brake that is activated by the release of the throttle linkage or trigger, which does not address the problem of injury or damage by a chainsaw that is dropped by the supporting hand.